Ola C. Landgren, MD, PhD Memorial Sloan Kettering Cancer Center Interview Date: January 12, 2017 

Minimal Residual Disease testing has become a buzz word in multiple myeloma. What exactly does it mean? In this show Dr. Ola Landgren, an MRD expert helps us understand the different types of tests, what the results show and how they can impact treatment. Dr. Landgren explains the differences between flow MRD testing and DNA MRD testing and how they could develop over time. He also shares how MRD testing could become a new and earlier end-point in clinical trials now that patients are living longer. Learn more about how MRD is measured and what it can mean to your myeloma treatment decisions in this highly informative show with a leader in the field. 

Thanks to our episode sponsor

Jenny: Welcome to today’s office of Myeloma Crowd Radio. A show that connects patients with Myeloma researches. I’m your host Jenny Ahlstrom. We’d like to thank our episode’s sponsor for their support in this program, Takeda Oncology. As you heard in our last show, more Myeloma progress means longer life for patients. This is a big blessing for patients and is exciting for researchers who are starting to use the word cure. Now, with more sensitive tests, researchers are now able to detect lower levels of disease. They are finding that these low levels can predict generalities about who will and won’t progress and how durable remissions might be. This opens windows of opportunity to customize treatment. For example, who needs more aggressive treatment or who can stop maintenance therapy? We’ll talk about these types of tests and the challenges that researches face in today’s show with renowned myeloma specialist, Dr. Ola Landgren. Dr. Landgren is a leader in minimal residual disease testing and Myeloma. He has helped advanced the field and knows how it can be successfully applied and advanced to Myeloma. Dr. Landgren, welcome to the program.

Dr. Landgren: Hi, Jenny. Thank you so much for having me. It’s a great honor.

Jenny: Well, thank you so much for joining us. I want to give a brief introduction for you before we get started if you don’t mind?

Dr. Landgren: Please go ahead.

Jenny: Dr. Ola Landgren is Chief of the Myeloma service at Memorial Sloan-Kettering Cancer Center in New York City and Professor of Medicine at the Weill Cornell Medical College in New York. Prior to his appointment at Sloan-Kettering, he treated myeloma patients at the National Cancer Institute for eight years and at Karolinska University Hospital in his home country of Sweden for two years. Dr. Landgren is a member of the International Myeloma Working Group, board member, and NCI Representative of the Myeloma Steering Committee, part of the Hematologic Malignancies Program and the Clinical Investigation’s branch of the NCI and the NIH, member of the Association of Medical Research Charities and board member of the CCR, clinical research strategic planning committee. He’s received many awards including the Director’s Intramural Research Award by the NCI, the NCI Bench-to-Bedside Award and the American Society of the Clinical Investigation Award. He has many open studies at Memorial Sloan-Kettering. Dr. Landgren, in one of our first shows, in 2013, you really pushed the idea and wondered why doctors were not treating with a goal of a cure or treating with the idea that a cure could be found. Here we are several years later and lots of people now are talking about a cure.

Dr. Landgren: Yes. It’s kind of interesting how things go, isn’t it? You have to aim high and then you just keep on working hard. That’s I guess how life goes.

Jenny: Well, you’re an expert in Minimal Residual Disease and that’s the topic for our show today so maybe you want to give us a broad overview of what minimal residual disease testing is and what it tells us generally.

Dr. Landgren: Minimal residual disease testing is a terminology that has been used in several other diseases for quite some time. I think good examples could be, for example, the acute leukemias and also I guess HIV is another good example. With better therapies, doctors have recognized that the amount of disease that a person could have in his or her body keep on shrinking and using conventional definitions for a good response which in different diseases is defined a little bit differently but usually called “complete response” meaning that there is no disease detectable by those definitions. Although patients meet those complete response criteria, with the more sensitive technologies doctors found that there could still be some residual disease. That kind of opened up this whole field of Minimal Residual Disease detection. Over time, it was found that you can keep on pushing beyond complete response and you go lower and lower and eventually you will not find any disease if you have successful therapy in a given assay and studies have found in different diseases including myeloma that the outcome, the progression-free and overall survival correlates with that depth of response so it’s really a way to measure how well the therapy can get rid of the disease, that’s what it is.

Jenny: When you’re talking about MRD positive or MRD negative maybe for those who aren’t familiar with those terms, it’s pretty clear what it might mean but how would you define that?

Dr. Landgren: The way MRD for Multiple myeloma is defined that is based on the document that we wrote together in the International Myeloma Working Group and we published mid last year 2016. We were all in agreement that it was time to put down the foot and say MRD has come to stay in the field of myeloma. With that statement, we also had to define how to determine MRD positive, negative in order for every study to be consistent so you can compare therapies from different trials using the same end point. That’s very important to have consistent end points. This criteria in this document I’m referring to says that one has to use technology and that technology has to be sensitive to the degree that it can find one cell in hundred thousand and it’s based on bone marrow aspirates so in practical terms, that means that the doctor will conduct or a nurse practitioner will conduct a bone marrow aspirate and you will take that sample and you will process it the standard way and it will now not only be evaluated out of the microscope with conventional flow cytometry assays that are done around the world, we will also now expose that sample to a Minimal Residual Disease assay, that can find one cell in a hundred thousand evaluated cells. The document says that if you use a flow cytometry-based, or what’s called a DNA Sequencing base technology, either of those two is fine as long as the assay can find one cell in a hundred thousand or better. The consensus is when it comes to flow assay that if less than 20 cells have the features of being suspiciously abnormal, if it’s less than 20, you still call that negative and that’s because of the nature of the cells that it can sometimes be very difficult to distinguish a normal from an abnormal cell which is actually not a matter of finding zero versus finding one. The threshold goes to 20 and it comes from extensive work in other diseases as well. That’s kind of where the cut off is. When it comes to the Sequencing, you use readouts from what’s called VDJ sequences so you don’t count cells, you count DNA sequences and you have to have a baseline sample and then you profile all these so-called VDJ sequences and every B cell in the body has its own VDJ sequence. These are also part of the immune system and the reason there is a big range is because we’re constantly exposed to a lot of things in our bodies, things that come from the inside and things from the outside of our bodies, from the environment. So the immune system needs to be very, very broad and flexible. If you look at the myeloma population in the patient, amazingly every cell virtually seems to have the same VDJ sequence. There’s a lot of genetic heterogeneity across the tumor cells but when it comes to the sequence of what’s called VDJ, that particular region in the genome seems to be virtually identical in every cell in a given patient. It differs from patient to patient but in the person it is .So if you do the baseline and then you treat and you take out cells and you run the assay again, if you no longer can find any such excess copy number, more copies of that VDJ that we found in the beginning, then you can say it’s MRD negative. Lastly, along these lines, the sequencing has probably a ten times higher sensitivity and it may not sound like a whole lot but that means that you can rule out one cell in a million instead of one cell in a hundred thousand. It actually is very, very sensitive. That’s how you distinguish positive from negative.

Jenny: And you just do what your baseline is before and after treatment.

Dr. Landgren: Because you are looking for these sequences for VDJ which is a particular area in the human genome and that is being differentially used in different cells of the immune system so you cannot really know if you have a person who has been successfully treated for myeloma, if you just take a look in that sample, if everything looks fine, there are still some blips up and down and some of those blips could be because there are normal cells going up and down so you need to have a baseline sample in order to reliably say that the clone that was there from the beginning is gone. The sequencing, although it’s more sensitive, one of the limitations with that technology is that you need to have a baseline sample. On the other hand, if you do work up to begin with, you do a lot of other tests. The doctor has to remember to do that so you have that available. It can be done later. If it was not done, a diagnosis can be done if the person has a relapse, you could do the test and then if you re-treat, you can do the same thing again so it doesn’t have to be necessarily from the original diagnosis but there has to be some disease in the sample.

Jenny:  Interesting. So you know what to compare it to. When you compare these two different kinds of MRD testing, which do you prefer? The flow or this DNA sequencing? Which came out first and can you give us a little bit of history about how they were developed?

Dr. Landgren: The early work comes from the United Kingdom. The group in Leeds led by Andy Rawstron who is a flow cytometry expert. He’s a good friend of mine. They did this in the 1990s. The Spanish started copying their approaches and they started playing with it and they developed more advanced flow cytometry and they started seeing how many antibodies do you really need to put in the tube. So in brief, when you look at the surface on the cell, any cell in the body, there are certain proteins that are expressed and if you look at the myeloma cell versus a regular cell let’s say in the skin, they have different signatures. If you look at the normal plasma cell versus the myeloma cell which is an abnormal type of plasma cell, they are not identical either. The problem is that every person has a little bit of a different protein repertoire on the surface and that’s true for myeloma itself. Every myeloma patient have different myeloma looking cells so you couldn’t just have one marker and look for that, and look in every patient and find the answer so that way you need to have a whole series of these markers. What the Spanish found was that if you had one marker, that’s not good enough. If you have two, that’s better than one. Three, that’s better than two and then they kept on going and they were combing different antibodies back and forth and they realized that if you have ten antibodies after a lot of work they found out which were the ten best, that is better than nine, but when they went up to 11 and 12 and 13, it didn’t seem to make a whole lot of a difference. They said ten is really what you need to have and these are the ten. They did a lot of work on that. The problem with the work they did was that the machine they had could only read eight at the same time so they had to split the sample from the patient in two different tubes so they took half the sample in one tube and half the sample in the other tube. The first tube, they took eight of their colors and then in the other tube, they took the additional two and then they took again six of the first ones from the first tube in that second tube so you have eight. For every patient, it’s been tested in two tubes but there are ten colors. So if you run a laboratory for example with 2,000 tubes, that could either be 2,000 patients if you could do one tube per patient but in this case, it turns out that you can only do a thousand patients because each patient has to be two tubes. It sounds kind of simple but the reality is that this is how they developed the technology. The problem with that technology is that it’s a lot of work and you have overlap with these antibodies, they’re also quite expensive, but this is really what this EuroFlow method is. It’s very sensitive, it has figured out antibodies and it has a lot of the data to back it up. It is not so easy to do in the laboratory. It is actually very difficult. At this point, there are probably only five or six labs in the United States that really do it right out of all the laboratories which is almost nothing. I think in Europe probably five or ten labs also. I think the future of flow cytometry, I do personally think, and this is an opinion, I don’t think that it’s going to make it as the final test. I think this has a lot of limitations because it’s practically very difficult. I think the sequencing technology is very different. It’s much more reproducible and it’s easier to run in the lab. You can have a kit, you take the sample, you extract the DNA, you put in the kit, and you run it in the machine. Here’s the data. It’s much more simplified. At this point, unfortunately, there is no technology that is available for myeloma commercially yet but there are a lot of companies that are developing this so I think within the year or so, this would probably take off and it’s just going to keep on going. That’s what I think.

Jenny: If I were to get MRD tested today, it’s most likely just the flow because the DNA really isn’t available? Are people using that in clinical trials though? The DNA sequencing?

Dr. Landgren: Flow is really the only thing that’s available. The problem is that the technology flow has been invented since the ‘70s or ‘80s, it’s a very old technology. The problem is really to follow all these steps and to do everything that was proposed in this model by the Spanish group, the EuroFlow. That is not followed in most laboratories. There is a lot of the variation unfortunately. Yes, if patients go today, that’s usually what is done. They try to either replicate that or do some other home grown model. Sequencing is not yet commercially available and once that happens, my prediction is that that is going to take the whole field forward.

Jenny: Because it’s a more sensitive test. Now, does either one of these, are they measuring quantity only or can you measure the type of myeloma? I know myeloma changes over time when you said a patient will have different kinds of myeloma, different proteins, different clones, I guess people call them sometimes. Does it measure the type of clone or is it just measuring quantity itself?

Dr. Landgren: VDJ is a particular region in the genome. If you have a person with multiple myeloma, you do what’s called whole genome sequencing, you capture all the DNA information or you do targeted areas. You could either do the exomes or you could even do customized exome, you could do subset of the exomes. However you do it, you will see that each and every person with the new diagnosis of myeloma probably has at least ten different clones at diagnosis. This is true for every patient. Every clone has different mutations. For reasons that we don’t fully understand, in each and every clone, the VDJ sequence seems to be virtually the same in every cell in a given person but between people, the VDJ is different but in that person in it. If you use VDJ for MRD testing, you cannot study the diversity of the disease. You will only be able to track if it’s there or not with the limitation of the sensitivity and if it’s there, you can translate that into quantitative measure say how many copies you find which you can use to predict the volume of disease. Flow cytometry, these ten antibodies colors I mentioned, they are not exactly expressed on the surface of every cell across patients of within the given person. They are not linked to that genetic heterogeneity I’m referring to so if you do this sequencing I mentioned and you do flow cytometry, even if you split the sample in many subsets, each and every subset of disease genetically do not have different protein markers. They could have identical same protein markers although they are genetically different. When you say follow subsets of disease, you can follow whatever subset you see but if you’re after the genetics, then flow is not going to do the job. But maybe flow is good enough. Maybe sequencing is good enough. My gut feeling is that if we can drive down the disease with non-detectable, with a very sensitive assay such as sequencing VDJ, if that still is residual disease, if we took that out, we could then sequence those residual cells and see what they’re like. That is technically possible. It’s not easy but it’s possible. We are working on these types of assays.

Jenny: You’re working on those types of tests?

Dr. Landgren: Yes.

Jenny: Interesting. Well, earlier you mentioned the International Myeloma Working Group guidelines that were changed last year, do you want to explain what those changes were and what are the current MRD guidelines?

Dr. Landgren: Up until mid-2016, the deepest response that was in the response criteria by IMWG which are the consensus criteria for evaluation or response on clinical trials, it used to be what’s called stringent complete response. That meant that the M-spike should be gone if the patient had an M-spike, that’s true for 80% of myeloma patients and if you did a bone marrow, you should have less than 5% plasma cells in the bone marrow, if you did flow cytometry on top of that, you shouldn’t be able to pick up any abnormal cells even if there were less than 5% and if you didn’t do flow but you stain for what’s called kappa lambda, you shouldn’t see any abnormal pattern there. On top of that, if the light chains were skewed to begin with, they have to be normalized. That would be the same as stringent complete response. What became evident over time was that in that group of patients, if they had just reached that level of response, depending on if they just barely reached it or if they really were much deeper responders on that, you obviously wouldn’t be able to distinguish that if you only use these markers but if you could theoretically think that the response would really deep beyond that threshold so when people start using these assays with flow cytometry, they saw there was a gradient, people that were positive or negative. Therefore, the International Myeloma Group criteria said: let’s move the bar beyond stringent complete response. Let’s now set MRD negativityas the highest level of response. The criteria are the following way. Number one, first, complete response has to be established. You need to rule out the M-spike and you need to do bone marrow showing less than 5% plasma cells. Second, now you take that aspirate and you run an assay that can find one cell in a hundred thousand or more sensitive so you could either do the flow or sequencing. If you do either of those two and the test is negative, now you can declare MRD negativity, so that’s the criteria. Basically complete response and a test can rule out one cell in a hundred thousand. The criteria also have two other aspects in these documents. Number two is that for patients who were worked up at baseline who did a PET/CT, if there were areas that have a normal FDG uptake, meaning that they were hot in areas where there was bone involvement that could be seen by CT, if you treat that person and the person is now in complete response, you do that assay and the aspirate and you conclude it’s MRD negative, the way I described it, you can first of all say the patient is in MRD negative state. If you now repeat the PET/CT, if those areas that were PET positive no longer are PET positive (the SUV has normalized), you could now say that not only is the person MRD negative, the person is also PET/CT and MRD negative. There’s less information known what that really means. There are some smaller studies saying that the PET/CT also has some impact on the outcome. What’s known from MRD in the bone marrow is that it clearly, strikingly correlates with both progression-free survival and overall survival. PET/CT is less well described and there are also a lot of technical problems with PET/CT. It has a lot of false positive and false negative so PET/CT I personal think is not really as well developed but people still put it in that document. We had a lot of discussion whether it was appropriate or not and the people who felt it was, they were in majority so that’s why we put it in but we also put language in and said that there’s more work that needs to be done. The last thing is that we had a lot of discussion on the value of repeating MRD testing. Going back to the first part of this two, when I talked about bone marrow based MRD and the PET/CT component on top of it. We were all in agreement that the bone marrow test was very important to declare MRD negativity. To build on that, we agreed to have the third out of the three parts in the documents, so to sustain MRD negativity was added. The way we defined that in the document was that if you repeat the bone marrow test and you look for MRD status, if you do that at least one year later, you can then say that you have sustained MRD negativity. We also said to follow up on that that if you do it, let’s say after 2, or 3, or 4, or 5 or whatever years, you could say that at two years, the sustained MRD negativity rate was this or that many percent in the study. At five years, you have this rate of MRD negativity being sustained. That really summarizes the whole document.

Jenny: Well, I think just to give people some context about why this is so important and you’ll do a better job at this, when you create these clinical trials, you’re trying to determine at what point you can call someone either Progression-free survival or overall survival, complete response, very good partial response. These are some of the measurements that you use today. What you’re saying is you’re looking for different and more sensitive criteria to be able to, in more detail, separate patients out so that you can see deeper levels. For example, like what you just said, if somebody’s two or three years out MRD negative compared to somebody who is in MRD negative status for six months or something, maybe you want to just describe a little more how you could see using MRD status as a clinical trial tool.

Dr. Landgren: What is already implemented in this International Myeloma Working Group Guideline is that any clinical trial that is written around the world that focuses on patients with multiple myeloma, if that study is following the rules, that should use these criteria to describe how well the therapy works. There’s no option there. It’s like you have to do that as an investigator. You cannot write a protocol and come up with your own criteria. That’s not right. The companies have to also use these criteria. Whenever you look, for example, if you could give therapy for four cycles and you evaluate how patients on a trial have responded, these are the criteria you have to use. You have to say partial response, very good partial response, complete response, stringent complete response, or MRD negativity rates. These are the criteria. If you do it at one year or two years, this is kind of the “law” for clinical trials. There is no penalty, no one is going to enforce any penalties but investigators will say, this study was not done right. No investigator would deviate from that. They will always do that. We have all agreed to do it. To make it consistent, to allow comparison across studies. It’s very important. That’s how that goes but the question that I think also comes up in the head of both patients and doctors and families and others, I do think could be for example, for a person who is not on a clinical trial, if he or she is MRD negative, how does that impact that person and how could that potentially impact the treatment? Now these are new questions that are not regulated in these documents. I see these a lot in my clinic. I see very many patients myself and we have a very active program here at our institution in New York. What we have done is that we have implemented MRD testing for every patient who comes to us so we took the Spanish model and we installed the machine that can read all the ten colors in one instrument and then we built the single tube ten color flow. We made a decision, almost three years back now, that we’re going to do this for every person, it’s going to be part of our standard of care. We treat patients, we check the blood test, if the M-spike becomes negative, we would do bone marrow tests and we will always run these tests. When we started seeing the data that was generated by the others and we looked at the data that we generated internally, we felt that if we could rule out MRD negativity after six cycles of combination therapy in a newly diagnosed patient, we felt that it was very reasonable to collect the stem cells and to offer the patient to either get the transplant with maintenance or to keep the stem cells and go right to maintenance. That’s a very bold move to do that. We feel, based on the data that has been generated worldwide among our colleagues and internally here, that there is no clear-cut benefit to the degree that we have to mandate the transplant in this setting. We think it’s still a valid option but we feel that there is no survival benefit from all the data and there probably is no progression-free survival benefit either but it is not from randomized Phase III Trials but from the studies that have been generated, all the data points to the direction that for people who reach that degree of response after combination therapy that the therapy itself may not be as important as the depth of the response. If you reach that deep response with whatever therapy you got to reach it, that’s all that matter so MRD is more important than the therapy. We let the patients make the decisions themselves.

Jenny: Is it more important than the duration of it? Like let’s say somebody has six cycles and then they become MRD negative, and they stayed that way for a year versus two years or three years, have you dug a little bit more into it to see if you just found that comparatively everywhere from the data that you’re talking about or have you gone to say, depending on how long they stay in that MRD negative status, it has an impact? Does that make sense?

Dr. Landgren: There are many very questions and we don’t have all the answers to all the questions so the answers that we have -- or the questions that we have answers to are, is MRD important? The answer is yes. It seems to correlate with longer progression and overall  survival. We have published on that. We have studies that are ongoing also. Other groups have the same, exact same results, identical results. The data I’m mentioning, there is no randomized Phase III Trial to prove what I just said at this point that MRD is more important than therapy but looking at the data, our interpretation, our expert interpretation of the data is that that is a reasonable conclusion. When we treat patients, we do a test after six cycles, and if they’re MRD positive, we counsel them towards transplant. If they are negative, we give them the option to decide. Every patient will see both the transplant doctor and the myeloma doctor and we don’t have the ultimate answer but for patients who choose to collect the cells and keep them in the freezer, we will put them on maintenance therapy and I can descriptively tell you that we have a very large program. We have several hundreds of newly diagnosed patients coming to us every year. Patients seems to have MRD negativity for very many years with either of these approaches as far as we have seen so far.

Jenny: That’s great. What amazing information.

Dr. Landgren: The future will tell and now, there are a lot of questions that of course come after -- it was one thing, you can ask new questions: so is that true for every person? It may not be true for every person so is it true if you have high-risk disease or standard risk disease? I think it may have different implications but we have also seen that there are patients that have what people refer to as high-risk disease that do equally well once they’re MRD negative, it doesn’t seem to really matter as much but it may not be the full truth and there is no randomized study to answer the question at this point so these are expert recommendations and patients are not being pushed in either way. They have the option to make their own decisions and we of course help them and work with the patients but this is where we are right now.

Jenny: Well, that’s a great example.

Dr. Landgren: I think there are a lot of other questions that we are kind of facing so for people who have been MRD negative for a long time, the question that many times come up, I have patients being MRD negative for five years, they never did transplant. “Can I go off therapy?” I don’t know. There’s no randomized data at this point. There are patients that have opted to go off and we have some patients that have been off for about two years now and to my knowledge, with the exception of a handful of people, those patients remained MRD negative a few years out so that is of course extremely, very intriguing. I’m not saying that this is the way to do it, this is the final answer. I don’t say that. I caution repeatedly and say we don’t have all the randomized data, we’re at the front of the knowledge where the knowledge goes into the unknown and we are just trying to build on what we know so we are very, very, very careful and we’re trying to follow this carefully. As a consequence, we are trying to develop blood based tests because if you want to monitor safely, I think you would like to make sure that the MRD negativity stays negative so we are quite far along with blood based tests for MRD testing so that would allow us to do much more frequent tests than if you normally would do a bone marrow, that’s something that you probably wouldn’t do every cycle or so but the blood based test could be done more frequently so I think that’s going to be majorly important going forward. The blood based MRD tests.

Jenny: That would be huge. That’s huge. Because you could check it monthly or twice a month or something like that. That would be incredible. How long do you think it will take for those types of tests to come to either clinical trials or the clinic?

Dr. Landgren: Well, we are working on it here internally. We are trying to get grant support, to develop these tests. Unfortunately, it’s quite cumbersome to do it so we need to have people hired, and we need to have machines and technology so unfortunately, everything that is involved when it comes to development comes back to grant funding, that’s unfortunately how it goes. I would say if we had sufficient funding, we could probably have these assays in one or two years for sure very far long with the current development rate. It may be more up to five years or something. I don’t really know. Something like that. I wish it was faster.

Jenny: Wow, okay. I know that you talked about becoming MRD negative is the goal, you can be MRD negative but progress and then you can be MRD positive but hold steady, so in your practice and in the data that you’ve seen, what does that mean? I don’t want patients to be really nervous if they’re MRD positive but they hold that for a long period of time or be MRD negative and like you were saying, you have to be very careful about stopping treatment and you’re very cautious and you put a lot of thought into it before you stop treatment. What’s your opinion on both of those? MRD negative and positivity?

Dr. Landgren: Well, I think you ask very, very important questions here, Jenny. All doctors who have treated patients for many years with myeloma have seen that here are patients that don’t necessarily have even a complete response. You can have let’s say, 0. -- I’m making up an example. 0.4 grams /dl of an M-spike, it could just be sitting there, year after year after year. The person may even be on maintenance therapy and the protein is there. All other levels are fine. The person is feeling great. It’s almost like MGUS. If you, in that case said, “Oh, let’s get rid of that protein,” and you started doing very aggressive treatment and you did a lot of things, I don’t think that would be the right thing to do because it’s really only that protein that’s there. Everything else is fine, the person is feeling fine, all other labs are fine. That’s one extreme. We see people that could also be MRD positive like that. You could be MRD positive for years. In practice, we have all these examples of people who have proteins or MRD positivity over long periods of time. That’s a true statement. At the same time, if you just look across the board, if you have a thousand patients and you treat them and then you have let’s say 500 of them are MRD negative and 500 of them are MRD positive, on average, the people that are MRD negative are going to have the longest progression-free survival. Within the group of those that are MRD negative, that could unfortunately be people who still do progress and in the group of MRD positive, that could be people who have a stable MRD positive like I just explained. When we provide or when we deliver these statements that MRD negativity is associated with better outcomes, these are averages. I do think really what happens is that we are approaching a dilemma or exposed to dilemmas in life in general, we approach them. We try to solve the problem. Not always do we reach the goal but sometimes it turns out that even if we didn’t reach the goal that the outcome is quite good anyway. That’s kind of how it goes but I think that is not the same as saying I’m approaching a problem here. I don’t care. It doesn’t matter because even if it’s still there, it’s the same outcome. That is not the same thing. I think you do your best and there could be a little bit left behind and that could still have the same good outcome but you always try your best. I think that’s kind of how it goes so the two different kind of paths you end up with the same results but the approach is different. Does that make sense?

Jenny: Yes. It makes sense. I had another doctor say that when he was treating high-risk patients, it was more important for his high-risk patients to hit a complete response with the standard criteria without MRD then it was for his average patients or standard risk patients to achieve a complete response because some of those could stay with a little bit of M-spike or something for a long time but it was more important for the high-risk patients. When you’re looking at MRD levels and somebody’s positive, say, are you looking for just trends up or down or people holding study at certain levels? What is an indicator to you if somebody’s MRD positive about the treatments that they need like you said you’re offering stem cell transplant if they’re MRD positive and then they continue on with treatment or do you use that as a marker to know how much therapy to give the level of MRD positivity or I guess then your backup and if it gets too high, then you're into the regular testing, right?

Dr. Landgren: At this point, there is no randomized data to guide doctors how to do these things. Everything we’re talking about right now are scientific hypotheses and these are things that are currently being tested in some clinical trials and I do predict there’s going to be more and more focus on this question. There is no answer from randomized studies to answer all these questions you ask. They’re great, great questions. I cannot give any numbers or any firm result in the absence of data or I think that the questions I see are, for example, the person who gets treated with combination therapy and has a very good response, who’s MRD negative, do you need to go through additional aggressive toxic therapy or can you go right to low intensity therapy such as maintenance? That scenario, I outlined, we made a decision at our institution to offer patients both and they can choose so that’s an example of how you go from aggressive to more gentle therapy if you are. For a person who is MRD negative, that term “MRD positive” is that something that should be viewed as an indicator that you maybe need to start thinking about retreatment. This is a new evolving area. We don’t know so there is some early data suggesting that if you convert that maybe that could be a prodrome of a biochemical relapse meaning that the M-spike will come back and that could take another month or half a year or a year or something. It varies a lot and if that happens, then that will continue to go up and then eventually, you may need to start therapy or you should have certain developmental symptoms that will trigger you to start therapy if you’re holding off so these windows are not well defined. I think they probably range from a few months up to maybe one-two years or something. Studies need to be done and I guess the studies need to not only look at how to put out the fire but also I think importantly, it’s going to be much more focused on wellness, quality of life, so you cannot just throw in a lot of toxic things and get rid of a protein. If the person feels fine, that is not necessarily right at least not for every person. It has to be put in context there. These are very important questions that need to be address both molecularly, clinically from the end point point of view and also from the quality of life and wellness perspective in my opinion.

Jenny: Right. Well, there’s a lot of think about. It’s very obvious to me that we need myeloma specialists in our corner and I say this almost every show but I mean it. I just think the level of specifications that someone like you has versus someone that is treating 20 different cancers, they just can’t know this level of detail. I appreciate it every time I talk to someone on a radio show. Thank you for going to that level of depth in your expertise. It’s amazing. Maybe you want to talk about how often MRD testing should be done and when and is there any time where it’s not useful or you shouldn’t ask your doctor about it?

Dr. Landgren: The way the criteria have been written and  these are the criteria I talked about several times today, they say that first of all, the patient has to be in complete response. That’s a kind of a requirement for these criteria to even be able to say MRD negativity. If someone has an M-spike, a light chain disease circulating in the blood and/or in the urine to do this test is not going to deliver MRD negativity. It will always be positive. It requires complete response in order to even be a candidate to be MRD negative by the criteria. I think a practical answer is that make sure you’re first in complete response and then you check. The question you ask about how often you need to repeat or do you need to repeat, I mentioned there is the sustained MRD negativity that was in the criteria we wrote, and we said that you need to do it at least a year later, you cannot do it two weeks later and say it sustained. It has to be the time window that we agreed to do a year. This is just how we agreed and it could have been differently but that’s what we agreed to do. For that reason, I think it’s reasonable with the bone marrow base test to offer people that are MRD negative to potentially check annually if the person wants to do it. I don’t think it’s by far at all mandatory. It is not. Outside clinical trials, there is no mandatory tests at all of course. In my clinical practice, patients who come and see me at our institution, we do MRD testing for every patient. It’s built in to our standard of care and we have the best technical assay set up. We do that. We treat them for six cycles, we do that if they’re negative, they go on maintenance or if they do transplant then they do maintenance. After a year, we would offer to do it again and in 99.999% of the cases, this is covered by insurance to do a bone marrow test and once we do the bone marrow test, our standard of care is to use part of the sample and run our MRD tests. That’s what we offer. We don’t force anyone to do it but we offer that here.

Jenny: Well, a lot of times you're getting the bone marrow biopsy anyway because you’re trying to detect level of plasma cells and stuff. The only time you are saying is not just useful at all if you have active disease whether that’s an M-spike or you’re saying activity in the light chains?

Dr. Landgren: That’s correct. If the light chains or the M-spikes are elevated, then there is no MRD to be talked about because it requires that you get treatment.

Jenny: Right. You have something.

Dr. Landgren: I mean the link is really that those proteins come from somewhere. They come from the cells in the bone marrow so if you see the proteins, you already know there are cells in the bone marrow. If you don’t see the proteins, then you go back and see if there are still cells but there are too few to leak out enough proteins so you can detect it. It’s all about detection. The assays, the flow assays, if you do them perfectly correct, you can find one cell in hundred thousand. Our flow assay can probably go in the range of one cell in hundred thousand and close to one cell in a million. We have spent a lot of time trying to calibrate that. The sequencing can go to one cell in a million. We don’t know if you go deeper, if that’s going to continue to correlate with better outcome. That’s where we have our blood based tests in development and we are trying to improve on that. But these are questions I don’t know the answer to.

Jenny: I know sometimes patients will see little blips on their like a light chain number will go up and then back down or something like that. If you’re doing the MRD and it’s positive and you have some of that light chain stuff going on, is that an indicator like if you repeated an MRD test, it was positive once because there’s a blip and it goes back down, will an increase in the MRD positivity status indicate that there’s disease growth because it’s more sensitive than the light chains?

Dr. Landgren: The first part of your question here, so the light chains are extremely volatile. They are not stable at all. If you check the light chains in a healthy person every ten minutes is going to show different numbers. If you check it in the patient with myeloma, it’s going to show different numbers. If you show it in someone in complete response, complete remission. With myeloma, it’s going to show different numbers all the time. Light chains are flying around all the time. If you have any infection that will drive up the light chains. If you walk around, if you eat if you drink fluid, if you do things, the light chains will go around. If the kidneys are busy filtering blood, the light chains will go up and down. The light chains are very, very unstable. So a blip up and down means absolutely nothing. The first thing to do is to just re-check it, and if it’s normal again, don’t forget about the blip. It was nothing. Light chains are not reliable. If you see, there’s a trend that they keep on going up. That’s a whole different thing but the blip has absolutely no impact. That’s always the case and a lot of other diseases, I’ve done research when I was at the NIH in many other disease areas such as various autoimmune diseases, I did research in HIV in the context of this proteins. You actually can see very high levels of light chains in people with HIV, you see it with different types of autoimmune diseases, with different types of other genetic immunological diseases we found it and people who underwent organ transplants and things like that. The light chains are absolutely not myeloma specific. They are associated with immune dysregulation or activation also. If the light chains go up and if you are MRD negative, that doesn’t mean that MRD went away. I would just recheck the light chain. If that’s normal, nothing has changed. If you see someone being MRD negative, turning MRD positive, if that’s something that could be a blip also, well, we know much less about that. I think if the person is on maintenance, it’s possible that it could go away. If it is in a person with outside maintenance, if it goes on to negative to positive, I have so far not seen it going away but I’m sure that that could be instances at least if it’s very low levels. If it’s just the rounded threshold of this sensitivity. There is very little data.

Jenny: I mean you’re learning as you go, right? Because you gain experience with patients and as these tests progress and become more sophisticated and more capable so I’m thrilled you have a test where you can do it in one tube, that’s great. How would a patient ask their doctor about getting an MRD test and what would you suggest that they ask for?

Dr. Landgren: As I mentioned, there are not very many centers in the country that do MRD testing at this point. We did a survey where we asked the 30 leading centers in the country and we did the initial survey we did a few years ago, about five years ago. When we asked the 30 leading centers, at that point, this is five years ago, 11 centers said yes, we do it but then when we started going through how they did it, only one of the 30 centers did it the way that the guidelines recommended so that was kind of disappointing. We sent out that same survey one more time and we actually sent it to the same centers and we thought maybe people were thinking about it again because they were asked then they knew that it was not that great. I do think that there were five or six centers that now would do it according to the guidelines but this is the leading myeloma centers in the United States we’re talking about.

Jenny: Right. They’re big. They have hundreds and hundreds just like you.

Dr. Landgren: There are very few centers that really do it at least if you mandate the guidelines to be right. I think if you go to a place where they don’t run the test the way it’s supposed to be, you’re very likely to be MRD negative but that could be false negative because they don’t find the cells. You’re talking about finding very low amounts of disease. You really need to have calibrated all the assays perfectly right. I think asking the doctor if they do MRD testing, if they don’t then that’s just how it goes. That’s 99% of the cases they don’t do it. If they do it, I guess ask where will the sample be sent and how will they be done. I’m not sure if all the clinical doctors that don’t spend any time doing research are fully aware. That I’m not sure about. I think that’s something that I guess patients could ask. Please be aware that this is an area where there is a lot of development so it’s not so easy for doctors that don’t have access to these technologies to offer it, it’s unfortunately, part of the evolution. I think in a few years, it’s going to be much more common but for right now, patients have to be aware of where to go if they really want to do it right.

Jenny: Right. Myeloma is rare anyway, right? I mean there are large myeloma academic centers but you’re talking about a rare disease and then brand new tests that are still in development and maturing as it proceeds. That’s terrific. Well, I would like to open it up for caller questions and give people a little bit of time to do that. I know I’ve taken a lot of time myself but we have a couple of caller questions, if that’s okay with you. Okay our first caller, go ahead.

Caller: Hi, Dr. Landgren and Jenny. This is Dana Holmes. Happy New Year to you both.

Dr. Landgren: Happy New Year!

Caller: I have a question for you. Is MRD testing subject to sample bias in the bone marrow as regular bone marrow biopsies would be?

Dr. Landgren: That’s a good question. When we talk about sample bias, that usually means that depending on how the test and the sample was collected and done would have impact on the results so the answer is that yes, it is. Now, that’s not unique to a lot of other tests. If you check hemoglobin in the person who got an infusion with fluid and you draw blood, the hemoglobin would be false also so every test we do could potentially be impacted by things that we also do. The variation for the MRD valuation is more sensitive than the example I gave, like if you just check the CBC. The things that could “be wrong” in an MRD sample could be that the person who does the bone marrow doesn’t follow a predefined protocol when they actually do these samples when the doctors have the syringe and that the marrow’s being sucked out from the marrow, if it’s not done right, there can be a lot of blood coming into the syringe and the blood will then dilute the sample so when you send over the sample to the laboratory they will look through more blood than actual marrow and then they say everything looks clear but it’s really because they’re looking at blood and not marrow so that’s a problem. Also, there’s less known about this but you could at least theoretically envision that in the person who has been treated successfully for myeloma, if the tumors all die off, there may still be some cells sitting in areas that are not consistently spread out throughout the bone marrow. When you put in the needle, if you happen to put a needle in an area where it has been clear and then you do all these tests and you say it’s negative, there could still be cells sitting elsewhere. That’s something that there’s really no way to overcome that with that technology but independent of those factors, and there are other factors as well. The machines have problems, they can what’s called “lyse” the cells and impact the cells and so you don’t find them. They may break in the machine. There are other things as well. Independent of that, all the literature shows that being MRD negative is associated with longer progression-free survival and also with overall survival so built in these problems, it still has a prognostic impact.

Caller: Will the blood biopsy overcome that eventually?

Dr. Landgren: Thank you for asking that. I was just going to say. The way to overcome these problems I guess would be exactly what you say to find another way of looking for it. I have worked on MRD assays for I think eight or more years now. We have spent a lot of time thinking about it. We have worked in the lab, we have done very many analyses and we keep on working. We are more active now than we have ever been in the past working on these different assays. We have been able to extract DNA from the blood and we have found the same signature in the blood as you can see in the marrow. We have found out that diagnosis, so we could actually see exactly the same as we saw with the biopsy in the blood. That’s pretty neat. The problem is when we treat, the amount of DNA goes down very, very much which is certainly a good thing. We kill the cells. If we have problems finding those last cells in the bone marrow, because we start off which much less DNA in the blood to begin with, it’s going to be even more difficult to find it in the blood. It becomes practically very difficult to find DNA in the blood and even if we have looked for single cells in the blood, that is also not easy to do. What we’re doing now is to see if we can actually find proteins that have been produced by the cells in the bone marrow that they leak out in the body and then we can track those proteins in the blood instead of looking for DNA from individual tumor cells, each cell is capable of producing a lot of protein so there is more protein than they have DNA inside themselves.

Caller: Amazing. It’s just amazing. It’s like building a pyramid.

Dr. Landgren: That’s now what we’re doing. I can tell you we don’t have the final results but we have done what’s called dilution series where we have diluted the samples like millions or more from what we started off but we still cannot find these proteins so we are very hopeful about that but we don’t have the final results.

Caller: Well, Dr. Landgren, what is it going to take to get MRD testing to be standardized because Jenny and I are active in these online Myeloma groups and we do hear patients say that they had MRD testing but they really don’t know to what level, if you ask them what kind of testing, nobody really knows so it doesn’t sound like we’re even close to comparing apples to apples when you have these discussions. How do you overcome that?

Dr. Landgren: I don’t think it’s that complicated but I think there are a few practical things that need to happen. I think, when the sequencing base assays become approved by the FDA, that will be the first step. That will take away all the problem with flow cytometry. Flow cytometry will, in my personal opinion, never make it. It will not happen. When a sequencing test comes, that will be the first thing and then the implementation of this in clinical practice will be the next. I think we are about one to two years away from these things coming in to full clinical practice. Until that happens, unfortunately, only patients who live nearby centers that can offer it or patients would travel to those centers will be able to be tested reliably. This is unfortunately how it is, just kind of a supply-demand dilemma right now.

Caller: My last question too, I don’t want to take up all the time, is from a smoldering myeloma patient stand point, do smoldering myeloma patients have a better chance of reaching and maintaining MRD negative with earlier treatment? Would that be related to the fact that their disease may not have yet mutated to a very complex level?

Dr. Landgren: Well, there’s much less known about that so what’s known about in very brief MRD in different stages of disease so the higher degree of MRD negativity comes from the study we did at the NCI. We published that in 2015 in JAMA Oncology and the MRD negativity rate in newly diagnosed patients, if you use 10 to -5, sensitivity was in the range of about 60% so 60% of patients have no detectible disease with the sensitivity of the International Myeloma Working Group criteria. What’s known in the setting of relapsed disease, there was a presentation at ASH in December in San Diego, they showed with the use of Daratumumab, Revlimid, and Dexamethasone that the MRD rate was 25% in people with one to three prior lines of therapy. This is in the relapsed setting. In smoldering myeloma, there is much less known. Again, the NIH study is the only study that has information at this point and that’s simply because you need to have powerful therapy and the first randomized study that was done for smoldering was the Spanish Revlimid Dexamethasone versus no therapy and the Revlimid/Dexamethasone is a very weak regimen so you don’t have MRD negativity with that therapy so it’s not meaningful to do it. The NIH study used Carfilzomib/Revlimid/Dexamethasone and that study showed 100% complete response. It was in the range of about 95% MRD negativity, 10 to -5. So those are the studies but these are all small studies. That study is so far has only enrolled 18 patients or so, the numbers may not be precise. They are not precise. These are the rates that we have based on data in the literature at this point.

Caller: Are certain molecular subgroups more likely to reach MRD negativity or is it just really based upon the treatment?

Dr. Landgren: I think all those factors matter. I think the treatment majorly impacts the study that I was referring to for the relapsed setting with Daratumumab, Revlimid, Dexamethasone, they broke down the MRD cases in relation to what they referred to a standard risk and high-risk and only in patients with high-risk did they see MRD negativity if they were treated with Daratumumab, Revlimid, Dexamethasone. None of the high-risk patients that were treated in that randomized study with Revlimid, Dexamethasone alone reached MRD negativity. The therapy is important. The second, as I pointed out also as far as example, it seems that the biology of disease is also probably important, and thirdly, as I also indicated if you look at newly diagnosed in the relapsed and in the smoldering setting, the rates go up in earlier disease. Probably, the amount of disease early not aggressive disease treated with optimal therapy. You are more likely to have high MRD negativity rate which I guess makes quite logical sense.

Caller: Yeah. Well, thank you so much Dr. Langren for your time as always. Find us a cure! We’re counting on you!

Dr. Landgren: Well, we are doing our best to try to improve. It’s not easy to do these things but I --

Caller: It sure doesn’t sound it.

Dr. Landgren: We are very excited about all these things I’m talking about and I do think that the future looks extremely bright for people both with smoldering and with multiple myeloma. There is more work to be done and we work as hard as we possibly can.

Caller: Well, thank you for everything that you and your group does. It’s exciting to hear about it and it gives patients hope. Thank you for that. Have a great day everyone! Jenny, thanks for taking my calls.

Dr. Landgren: Thank you.

Jenny: Thanks. Well, Dr. Landgren, we’re just so thankful that you joined us today. Your work is just truly incredible. I’m just so thankful that you’re working on our behalf and for all you do. Thank you for joining us today and going into such depth with MRD status. It’s just so helpful to hear it straight from somebody who knows all the details.

Dr. Landgren: Thank you so much for having me, Jenny. I hope you have a wonderful day. Thank you again for having me.

Jenny: Thank you so much for joining us. You’re terrific.

Dr. Landgren: Thank you.

Jenny: Thank you for listening to Myeloma Crowd Radio. Join us next time to learn more about what’s happening in Myeloma research and what it means for you.